Local television reported that they want to be integrated into the French public service.
Their action comes as senior public sector staff are in their fifth week of a strike.
Their union wants them to be integrated into the French public service under the so-called Sauvadet law.
They allege discrimination and have taken the French prefect to court, but he says there is a process to follow.
Firefighters have also been on strike for nearly a month, demanding better conditions.